1. Field of the Invention
The present invention relates to a device adapted to move the sharpening grinding wheels in a leather splitting machine close to and away from a cutting blade.
2. Prior Art
It is known that splitting machines substantially consist of a band blade disposed around a pair of flywheels or pulleys having axes substantially parallel to each other. The band blade has the function of carrying out a thinning cut in a leather sheet which is thereby divided into two layers one of them being generally valuable and the other having to be discarded.
As leathers to be worked are often very thin, it is indispensable for the band blade to act very precisely and for the blade bevel or cutting edge to be always perfectly sharpened. For the purpose splitting machines are provided with a grinding unit consisting of a pair of grinding wheels symmetrically disposed relative to the cutting blade bevel and continuously acting during the machine operation.
Grinding wheels are provided with adjusting means allowing them to be correctly located in relation to the blade bevel but they are mounted on a fixed supporting structure so that they cannot be moved away from the cutting blade when the latter is moving.
Owing to this fixed positioning of the grinding wheels in operative engagement with the cutting blade, it has been remarked that when the splitting machine is stopped, a sort of furrow or notch is created in the bevel which subsequently causes, when the splitting machine is again operated, undesired marks and engravings on the splitted leather. In fact, by effect of the respective inertias when the machine is stopped, the cutting blade tends to immediately halt, while the grinding wheels go on turning so that they sharpen the blade at one point only which causes said furrow.